在氨水潮湿面固化的胶粘剂——在处理小化肥厂“跑冒滴漏”的应用

小化肥生产中的设备、管辺等,或因本身存在的沙眼气孔等缺陷、或在各种温度下经水(火)气、氨水长期腐蚀、或在压力下遭受气液、物料和(火)尘的冲击等原因,均会产生腐蚀穿孔、泄漏损坏,从而导致生产过程中出现严重的“跑、冒、滴、漏”现象,大大地影响生产效率。目前,国内已有采用氟(木向)胶和硅楠胶的垫片制品代替石棉垫或盘根,对解决化工生产上的阀门和管辺连接卩位的泄漏问题,取得了良好的效果。但对设备和管辺的腐     

纳米材料与物理学

简述了纳米材料的发展过程,讨论了纳米材料的电子结构,提出了纳米材料研究中的物理问题。     

SELF-ORGANIZED FORMATION OF HEXAGONAL NANOPORE ARRAYS IN ANODIC ALUMINA

Conditions for a self-organized formation of ordered hexagonal structure in anodic alumina were investigated, using oxalic or sulphuric acid as an electrolyte. Highly-ordered nanopore arrays with pore densities of 9×10⁹-6.5×10¹⁰cm^-2 and high aspect ratios over 3000 were fabricated by a two-step anodization process. The array exhibits characteristics analogous to a two-dimensional polycrystalline structure of a few micrometres in size. The interpore distance can be controlled by changing the electrolyte and/or the applied voltage. The formation mechanism of ordered arrays is consistent with a previously proposed mechanical stress model, i.e., the repulsive forces between neighbouring pores at the metal/oxide interface promote the formation of hexagonally ordered pores during the oxidation process.     

基于互补型光栅编码的相位展开

为了解决在运用相移技术和二元光栅编码结构光进行相位展丌时存在的误码问题,提出了一种新的互补型二元光栅编码.通过多投一幅格雷码图案,并利用格雷码相邻码字之间Hamming距离为1的特点,没计出互补的两种编解码方式.利用两种编码出现误码位置的不同,并结合相移技术解决了去包裹过程中的误码问题.论述了互补型二元光栅编码的设计方法及特点,并详细分析了基于互补型二元光栅编码的相位展开过程.计算机模拟和三维重建实验清楚地表明,提出的互补型光栅编码能很好地解决了误码问题且具有很高的可靠性.     

AuPd CATALYTIC NANOPARTICLE SIZE EFFECT ON THE FORMATION OF AMORPHOUS SILICON NANOWIRES

Amorphous silicon (a-Si) nanowires have been prepared on SiO₂/Si substrates by AuPd nanoparticles / silane reaction method. Field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the samples. The typical a-Si nanowires we obtained are of a uniform diameter about 20 nm and length up to several micrometers. The growth mechanism of the nanowires seems to be the vapor-liquid-solid mechanism. The catalytic particle size effect on the formation of the nanowires and the cause of forming amorphous state Si nanowires are discussed.     

Shape-Controlled Synthesis and Related Growth Mechanism of Pb（OH）2 Nanorods by Solution-Phase Reaction

We present a simple method to synthesize Pb（OH）2 nanorods by solution-phase reaction. Rod-like lead hydroxide precipitates are obtained by mixing lead nitrate with a concentration of about 0.01 M and potassium hydroxide with concentration of about O.03 M in an aqueous solution. Sodium chloride as an additive is premixed with the lead nitrate aqueous solution. The presence of chloride ions in the precursor solution results in the rod-like morphology of lead hydroxide precipitates. The growth mechanism of the lead hydroxide nanorods is discussed.